The present invention relates to integrated retroreflective marking materials for fresh or hardened concrete and asphalt surfaces, such as roads, highways and the like. The present invention relates particularly to cementitious material formulations which contain a redispersible polymer and retroreflective/reflective materials.
Currently, the marking of concrete and asphalt for lane striping or cautionary markings is generally accomplished by painting stripes or applying preformed tapes of polymeric material. Disadvantages of these methods include the fact that both are temporary, requiring frequent, periodic reapplication.
To provide a longer lasting product, several marking methods include using a system which consists of a two part epoxy, thermoplastic, polyester, methyl methacrylates, or polyurethane resin system. Most of these products are solvent based or reactive resins which require special handling, storage, mixing, application and disposal procedures. With solvent-borne paint products, including the typical one-part traffic paint, the release of solvent into the environment with each application presents certain hazards to the environment as well as for nearby workers and applicators.
In some situations, retroreflectivity of the markings is desired, for enhanced night-time visibility. This has been proposed to be accomplished by several techniques. In one technique, preformed reflector devices are partially embedded in the roadway at regular intervals. The exposed portion of the reflector soon gathers a deposit of dirt or silt, which reduces visibility. The exposed portion of such a reflector may be damaged and worn away with repeated contact with vehicle tires, and cleaning or snow removal equipment.
Another technique is to precast a panel of concrete having reflective or retroreflective materials embedded into its surface, and then to position or affix the panel to the roadway surface or highway barrier. This requires custom prefabrication of the structures, and storage, transportation and placement of the heavy articles.
One onsite highway marking technique involves broadcasting a quantity of reflective or retroreflective materials onto the surface of a coating of paint applied to the surface of the roadway, optionally including a second coating of paint to lock in the particles. Similarly, it has been proposed to broadcast reflective glass beads onto a bonding polymer coating (such as epoxy) on the roadway, followed by application of a weathering top coat (such as a urethane). Again, these road markings are temporary, and require frequent reapplication.
A variant of the marking tape technique has been proposed, in which several layers of polymeric materials are adhesively bonded in the tape, at least one of which carries transparent microspheres or other reflective elements. In a related proposal, a single layer of polymeric tape carries embedded ceramic spheroids, to be used for marking lines on roadways.
These tapes are also temporary in nature, rapidly wearing due to the friction of vehicle tires, or pealing away from the roadway because of such friction or poor adhesion to the road surface. Due to the fact that these tapes are polymeric, they have different thermal properties than the substrate to which they are applied. In hot weather for example, preformed tapes tend to soften, collect debris, crack and delaminate. They can also require an epoxy-bonding agent to improve adhesion to the substrate. This complicates the application to the pavement, and introduces yet another thermally dissimilar material to the system.
Australian Patent 667210 proposes a surface coating composition for road marking, delivered to the site in two parts, one being a dry blend and the other being a liquid mixture. The dry blend includes white portland cement, titanium dioxide, refractory cement, and aggregate in the form of 150 to 600 micron sized garnet, or 250 to 600 micron sized garnet and 150 to 600 micron sized glass spheres. The liquid mixture includes acrylic cement polymer modifier, acrylate/styrene copolymer cement modifier, foam control agent, non retarding mortar, plasticiser and water. The two components are mixed onsite, and applied to the road as a paste. A stream of glass beads, 0.85 mm to 1.18 mm (850 to 1180 microns) in size are sprayed onto the paste to partially embed them for reflectivity.
There are several shortcomings with the marking material described in the Australian Patent. First, the fact that the marking material is a two phase system introduces variability and the possibility of improper dosage during the on site preparation of the paste to be applied to the roadway. The liquid portion, being susceptible to uncertain loading level, and being susceptible to spillage, is of concern to the environmental and structural integrity of the worksite. One must rely on the road crew to correctly measure and thoroughly mix the liquid and dry portions of the system, even if one could be sure that the correct loading levels of ingredients were present in the liquid portion.
Even if the liquid portion is pre-proportioned, it has to be mixed with additional water to achieve the desired workability. If the correct amount of water is not added, both the plastic and hardened properties of the finished product will be compromised. If the consistency of the marking material is too wet or too dry, the use of a liquid polymer as a primary component does not allow for any adjustments in dosage without affecting the performance of the finished product. The proportion of polymer in the marking material disclosed in the Australian Patent is quite high, raising concerns about the strength and abrasion resistance of the resulting product. The high polymer level also causes set retardation as evidenced by the use of a stream of hot air to accelerate the setting time and embed the glass beads. The hot air can cause rapid drying of the surface and differential hydration of the cement.
The glass spheres incorporated in the mixture of the marking material is more suitable for utility as an aggregate for the cementitious component, rather than promoting dry and wet night-time visibility and retroreflection, once the surface-borne glass beads are worn. Also, due to the ratio of garnet to glass beads used in the material, the small proportion of integral beads would be overshadowed by the larger and darker mineral aggregate after the surface is worn.
It would be preferred that a cementitious marking material be formulated as a one phase system, preferably a dry system, to ensure that the component levels were precise and uniform throughout, and to avoid storage restrictions (such as to prevent freezing) and transport of large quantities of liquid product with its attendant disadvantages of added cost and the need for disposal of plastic packaging containers.
However, the use of a significant portion of dry polymeric materials in cementitious mixtures presents other disadvantages. The polymer needs to be wetted out before use. The polymer often acts as a retarder for the system, and additionally, entrains more air in the cementitious mixture. Also, the polymer often presents a foaming problem.
It is therefore an object of the present invention to provide a marking material for fresh or hardened concrete or asphalt applications that is integrated, versatile in its mode of application, and long lasting with respect to the marked concrete or asphalt surface.
It is a further object of the present invention to provide an integrated marking material for fresh or hardened concrete or asphalt applications that can be stored and transported as a dry formulation.
It is a further object of the present invention to provide a dry formulation for an integrated marking material for concrete or asphalt applications that can be mixed with water on site for simple application to a road or highway.
It is a further object of the present invention to provide a dry formulation for an integrated marking material for concrete or asphalt applications that avoids the problems attendant with the incorporation of a large proportion of polymer in cementitious materials.
It is a further object of the present invention to provide a dry formulation for an integrated marking material for fresh or hardened concrete and asphalt, which can be formulated to meet various product application and performance demands.
It is a further object of the present invention to provide a dry formulation for an integrated marking material for concrete or asphalt applications that has high initial retroreflectivity when tested in accordance with ASTM standards (such as ASTM D-4061).
It is a further object of the present invention to provide a dry formulation for an integrated marking material for concrete or asphalt applications that retains high retroreflectivity even after wear of the exposed surface occurs.
It is a further object of the present invention to provide a dry formulation for an integrated marking material for concrete or asphalt applications that has high ultimate compressive strength, and is abrasion resistant.
The present invention therefore provides a dry formulation for an integrated retroreflective marking material for concrete or asphalt applications comprising a cementitious mixture including a hydraulic or cementitious binder, a redispersible polymer cement modifier, a retroreflective agent filler, and preferably, a reflective agent filler.
The present invention further provides a dry formulation for an integrated retroreflective marking material for concrete or asphalt applications wherein the polymeric cement modifier is a dry redispersible polymer selected from the group consisting of acrylates, methacrylates, ethylene vinyl acetate, styrene-acrylate, styrene-butadiene, polyvinyl acetate, acrylonitrile-butadiene, polychloroprene, vinyl chloride, vinyl laurate, vinyl versatate, vinyl acetate, and blends, copolymers, or terpolymers thereof.
The present invention further provides a dry formulation for a marking material for concrete or asphalt applications wherein the retroreflective agent filler is selected from the group consisting of glass beads, glass bubbles, glass flakes, glass spheres, ceramic spheres, plastic beads, fluorescent glass beads, fluorescent plastic beads, and mixtures thereof, wherein the retroreflective filler has an average particle topsize of at least about 600 microns.
In a preferred embodiment, the cementitious marking material is formulated to include both integral and surface retroreflective/reflective agents to ensure visibility as the surface wears with time.
In a preferred embodiment, the dry cementitious formulation includes at least one of an inorganic pigment, organic pigment, or inorganic/organic hybrid pigment. The pigment can be natural or synthetic.
The dry formulation of the present invention is capable of being applied to a pavement, highway or the like, by mixing with water on site and applying as a thin coating on the surface or as a thicker topping that becomes integral with the highway surface. The marking material, when applied to the highway or pavement, preferably has broadcast onto and embedded into its surface, additional retroreflective agents.
The present invention therefore provides a dry formulation for a cementitious marking material for concrete or asphalt, compatabilized for accepting retroreflective agents comprising a cementitious mixture including a hydraulic or cementitious binder, and a redispersible polymeric cement modifier.
The present invention further provides a cementitious marking material for concrete or asphalt prepared substantially onsite from a mixture of water with a dry formulation comprising a cementitious mixture including a hydraulic or cementitious binder and a redispersible polymeric cement modifier, said marking material having retroreflective agents at least partially embedded in its surface.
The present invention further provides an integrated marking material for pavement applications prepared onsite from a mixture of water with a dry formulation comprising a cementitious mixture including a hydraulic or cementitious binder, a redispersible polymeric cement modifier, a retroreflective agent filler, and preferably, a reflective agent filler.
In one embodiment, the integrated marking material of the present invention comprises a topping of at least about one eighth inch average thickness, preferably further comprising an at least partially embedded broadcast of retroreflective agent particles having a topsize of at least about 600 microns, preferably at least about 850 microns, at the surface of the topping.
In another embodiment, the integrated marking material of the present invention comprises a coating of less than about one quarter inch average thickness, preferably further comprising an at least partially embedded broadcast of retroreflective agent particles having a topsize of at least about 600 microns, preferably at least about 850 microns, at the surface of the coating.
In a preferred embodiment, the cementitious marking material is applied in a recessed groove or depression to make it an integral part of the substrate and to prolong its service life.
In a preferred embodiment, the integrated marking material includes at least one of a natural or synthetic inorganic pigment, organic pigment, or inorganic/organic hybrid pigment.
In an alternative embodiment, the present invention provides a dry formulation for an integrated retroreflective marking material for concrete or asphalt applications comprising a mixture including a hydraulic binder of at least one of magnesium phosphate cement and magnesium potassium phosphate cement, a retroreflective agent filler, and optionally, a reflective agent filler, as well as an integrated, retroreflective marking material for pavement applications prepared substantially onsite from a mixture of water with said dry formulation.
The present invention further provides an integrated retroreflective marking material for concrete or asphalt applications comprising a surface including a hydraulic binder of at least one of magnesium phosphate cement and magnesium potassium phosphate cement, having an at least partially embedded broadcast of retroreflective agent particles having a topsize of at least about 600 microns at the surface.
In order to provide a marking material for pavement applications such as for roads and highways, floors such as warehouse floors, sidewalks, toll booths, handicap spaces, parking lots, parking garages and parking decks, airfield runways and the like, that would be simple to apply, yet would last substantially for the lifetime of the pavement surface, it was necessary to develop a material that could be easily prepared onsite, and would have uniform properties throughout the application. The material would also need to exhibit structural integrity and strength substantially comparable to the pavement to which it was applied, and provide visibility both during the day and at night. The material would preferably exhibit retroreflectivity of vehicle headlamps that was substantially comparable to existing temporary marking materials such as paints and reflective tape.
I have developed such a marking material, particularly in the form of an easy to prepare, store and transport, dry formulation comprising a cementitious mixture including a hydraulic or cementitious binder, and a dry or powdered redispersible polymeric cement modifier. In a preferred embodiment, the cementitious mixture includes a retroreflective agent filler, and preferably, a reflective agent filler.
In the dry formulation, the hydraulic or cementitious binder is a hydraulic cement, preferably a portland cement such as that used for highway, bridge, or airfield runway construction, and the like, or quick setting cementitious binders such as magnesium phosphate or magnesium potassium phosphate cement, or any other suitable hydraulic binder. Suitable portland cements for use as the cementitious binder include Type I, Type II, Type III, Type IV and Type V portland cements. For specific marking applications, a white portland cement or a gray cement binder may be used. Other hydraulic or cementitious binders useful in the present invention include calcium sulfoaluminate (CSA) cements, such as type K cement, DENKA(trademark) cement, ROCKFAST(trademark) cement or ULTIMAX(trademark) crystal modified portland cement and calcium aluminate cements such as SECAR(trademark) calcium aluminate cement, high alumina cements, activated fly ash, activated clay, and slag cements.
An important ingredient in the dry formulation for the cementitious integrated marking material is a redispersible polymeric cement modifier, namely a dry polymer. By xe2x80x9credispersible polymerxe2x80x9d is meant a solid grade latex, such as is produced by spray drying a latex emulsion. When water is added to the dry polymer, it redisperses back to a latex emulsion. Examples of polymers which can be utilized as dry redispersible polymers include, but are not limited to, acrylates, methacrylates, ethylene vinyl acetate, styrene-acrylate, styrene-butadiene, polyvinyl acetate, acrylonitrile-butadiene, polychloroprene, vinyl chloride, vinyl laurate, vinyl versatate, vinyl acetate, and blends, copolymers, or terpolymers of these polymers. Preferably, the redispersible polymeric cement modifier is a dry acrylic polymer.
Examples of preferred redispersible polymeric modifier for use in the permanent marking material dry formulation include, but are not limited to DRYCRYL DP2903 or DP2904 acrylic polymer available from Rohm and Haas, ACRONAL S 420P flexible styrene acrylate polymer available from BASF, VINNAPAS SP-102 acrylic polymer or VINNAPAS SP-490 vinyl chloride polymer available from WACKER Polymer Systems and SB powder styrene butadiene polymer available from Rhodia.
The polymer cement modifier is useful to compatabilize the cementitious material with the retroreflective, and reflective fillers that are used in the marking material, but should not be present in amounts that would unfavorably diminish the strength of the resulting concrete material. The polymer cement modifier is therefore preferably present in the amount of about 0.2 to about 10% by weight of the dry formulation, preferably about 0.5 to about 8% by weight of the dry formulation when the binder is portland cement, and most preferably about 2 to about 6% by weight. The relatively low percentage of the polymeric cement modifier needed for the dry formulation according to the present invention, avoids the problems attendant with the incorporation of a large proportion of polymer in cementitious materials.
When the hydraulic binder is a quick setting cement such as magnesium phosphate or magnesium potassium phosphate, the polymeric cement modifier is preferably used in the amount of about 0.2 to about 2% by weight of the dry formulation. I have found that in contrast to the portland cement binder based formulations, that the magnesium phosphate or magnesium potassium phosphate binder based formulations having acceptable performance, may have incorporated or embedded in them, retroreflective agent filler and optionally reflective agent filler, without the polymeric cement modifier, or at least, with lower levels of the polymeric component.
As stated above, the polymeric cement modifier should be dry, such as in powder form, so as to provide ease of handling, measuring, and mixing in the dry cementitious formulation, and to avoid separation and resulting pockets of low strength materials in the final topping or coating product.
The dry formulation can contain other customary components of cementitious mixtures, such as aggregate, including fine aggregate or sand, and preferably also coarse aggregate, such as silica, quartz, crushed rounded marble, glass spheres, granite, limestone, calcite, feldspar, alluvial sands, other durable aggregate, mixtures of aggregate and the like.
The dry formulation can include various admixtures useful in cementitious mixtures, such as a dispersant, a plasticizer, or a water reducer, and/or one or more other common admixtures as needed for the particular application and environment, such as an accelerator, an air entrainer, a defoamer, fibers, an inert filler, a natural clay, a pozzolanic filler, a retarder, a rheology modifier, such as a water soluble gum or polymer, a shrinkage compensating agent, a synthetic clay, a suspending agent, a thickening agent, and the like, and mixtures of the foregoing. Suitable examples of these admixtures are known to those skilled in the art, and representative examples are listed in U.S. Pat. No. 5,728,209, incorporated herein by reference.
For durability considerations, the marking material dry formulation may include a pozzolanic filler such as fly ash, kaolin, silica fume, blast furnace slag, calcined clay and the like, and mixtures of such fillers. Other inert fillers can be included, such as calcium carbonate, ceramic microspheres, mica, talc, silica flour, diatomaceous earth, rice husk ash, and the like, and mixtures of these fillers.
In order that the marking material provide visibility at night or in other low light conditions, the dry formulation preferably contains a retroreflective agent filler, such as glass beads, glass bubbles, glass spheres, ceramic spheres, plastic beads, fluorescent glass beads, fluorescent plastic beads and the like, and mixtures of these retroreflective agents, for incorporation into the matrix of the cementitious topping or coating materials. To provide retroreflective properties throughout the life of the pavement to which the integrated marking material is applied, the incorporated, or integral, retroreflective agent has an average topsize of at least about 600 microns, preferably about 850 microns and up. The topsize of the retroreflective agent is limited only by availability and ease of incorporation into and mixing with the other components of the cementitious formulation.
Although it is preferred that the retroreflective agent fillers be introduced into the dry formulation at an early stage, such as during blending of the cementitious topping, it is within the scope of the invention that the retroreflective agents be introduced, with mixing, into the dry mixture of the cementitious binder, polymeric cement modifier, etc., at any time prior to the addition of liquid to the formulation. This can be accomplished, for example, by combining the preproportioned contents of a bag of the retroreflective agent and the contents of a container of the cementitious binder mixture at a job site, prior to adding the aqueous hydration liquid.
To provide improved dispersibility in the dry formulation, the retroreflective agent filler preferably has a surface treatment or a coating of a moisture proof, antistatic agent, examples of which include but are not limited to silicones, modified silicones such as alkylhydroxy silicones, carbinols, silanols, and the like.
To provide improved adhesion in the cementitious mixture upon hydration and drying, the retroreflective agent preferably has a surface treatment or coating of an adhesion promoter. Examples of such adhesion promoters include but are not limited to silanes and modified silanes, such as those containing functionalities selected from amino, vinyl, acrylic, alkoxy, alkyl, (meth)acryloxy, glycidoxy, methacryl, epoxy, acetoxy, methoxy, ethoxy, arylalkoxy, chloro, mercapto, carboxyamide, and the like.
Retroreflectivity refers to the process of reflection in which the incident rays and reflected rays are antiparallel. For example, a beam of an auto or aircraft headlamp that shines on the retroreflective agent is reflected back toward the source, being then visible to a driver or pilot. Not all reflective materials, and not all glass spheres are retroreflective. For glass spheres and the like, the minimum size to promote the optimum dry and wet night-time visibility is about 600 microns. Therefore, glass spheres that have formerly been incorporated into concretes as inert fillers, have not inherently imparted retroreflectivity to the concrete. To provide optimum retroreflectivity, the retroreflective agent filler, such as glass beads, preferably has a refractive index of greater than about 1.5, preferably about 1.5 to about 2.1.
In order to enhance visibility of the marking material, the dry formulation optionally contains reflective agents as filler to reflect light from other sources, such as smaller glass beads (less than 600 micron diameter), glass bubbles, glass flakes, glass spheres, ceramic spheres, plastic beads, fluorescent glass beads, fluorescent plastic beads and mixtures of these.
In order to function as lane or runway stripes or markers for hazards or other special marked areas, such as where delineation, accenting or site/area marking is desired, the formulation for the integrated marking material according to the present invention may include at least one pigment. For example, titanium dioxide can be used for white striping, and Hansa yellow for the yellow xe2x80x9cNo Passing Zonexe2x80x9d striping common to our highways. A black pigment can be used to provide contrast for an adjacent or overlaid white or colored material stripe, such as black iron oxide. For other purposes, the formulation may contain a pigment from the classes of fluorescent metal oxide pigments and phosphorescent metal oxide pigments, to create a xe2x80x9cglow in the darkxe2x80x9d effect.
The dry formulation may therefore contain a natural or synthetic pigment such as inorganic pigment, an organic pigment or an inorganic/organic hybrid pigment, including any suitable mixed metal oxide, dye or colorant. Such pigments include but not limited to, carbon black, Hansa yellow (2-[(4-methoxy-2-nitrophenyl)azo]-N-(2 methoxy phenyl)-3-oxo butanamide), chrome oxide, iron oxide, titanium dioxide, zinc sulfate, zinc sulfides, LumiNova(trademark) modified zinc sulfide (United Minerals Corp.), Lithopone zinc sulfide/barium sulfate, zinc oxide, titanates, nickel antimony titanates, phthalocyanines, mixed phase spinels and oxides, and mixtures of these, or any pigment meeting the requirements listed in ASTM specification C-979. The marking material of the present invention can therefore be tailored, in color and consistency, to meet special aesthetic or design needs.
The dry formulation generally contains the above described components in the following ranges, set forth in weight percents based on the total weight of those components listed: binder, about 15 to about 50%; redispersible polymer, about 0.2 to about 10%; retroreflective agent, about 10 to about 75%; reflective agent, about 5 to about 35%; aggregate, about 10 to about 70%; pigment, up to about 10%.
The relative proportions of the components are varied according to the requirements of the particular application, for example, as a thick topping or a thin coating, to fresh or hardened concrete, or to asphalt, and the end use performance characteristics desired in terms of strength and durability.
The integrated marking material for pavement applications, according to the present invention, is prepared onsite from a mixture of water with the dry formulation described above. The measurement of the dry formulation mix, and a quantity of water, is easier and more accurate than the calculation of a solids-containing solution or dispersion of uncertain concentration, together with the need to compatibly and uniformly mix the same. Of course, it is within the scope of the invention to include components in solution in the water that are not readily phase separable or critical in terms of absolute percentage to the dry formulation mixture, such as dispersants, plasticizers, water reducers, accelerators, air entrainers, defoamers, retarders, rheology modifiers, shrinkage compensating agents, suspending agents, thickening agents and the like.
The water cement ratio for the marking material is selected according to considerations known in the art for the particular binder utilized, generally ranging between about 0.22 and about 0.65.
The marking material of the present invention is therefore advantageous in that it can be stored and transported as a dry formulation and can be mixed with water onsite for easy application to the fresh or hardened concrete or asphalt pavement such as a road or highway.
The area to be marked can be prepared in a variety of ways. By one technique, the marking material can be applied as a topping comprising a mixture of water and the dry formulation to a freshly laid concrete surface, preferably in a slight depression as compared to the contiguous pavement surface, so that the marking material fills the depression to form an area having a surface approximately even with, or slightly elevated with respect to the contiguous pavement.
By another technique, the marking material topping is applied to a cured or hardened pavement surface, that has been prepared with a depression to receive the topping, or in which the depression has been subsequently formed, or cut.
By still another technique, a coating comprising a mixture of water and the dry formulation is applied to a pavement, such as an asphalt or a hardened or precast concrete surface, without the need for first preparing a ridge or depression to receive the marking material.
Techniques and equipment for applying the integrated marking materials of the present invention are also described in U.S. Provisional Patent Application No. 60/083,786 filed May 1, 1998, and its corresponding regular patent application U.S. Ser. No. 09/302,831, filed Apr. 30, 1999, now U.S. Pat. No. 6,213,680 entitled Apparatus and Method for Integrated Pavement Marking.
The marking material of the present invention, when applied as a thick topping according to the techniques described generally above, is of at least about one eighth inch average thickness, and is preferably one quarter inch or greater.
The marking material of the present invention, when applied as a thin coating according to the techniques described generally above, is generally less than about one quarter inch average thickness, preferably less than about one eighth inch in thickness. It is preferred, when the marking material is to be applied as a thin coating, that the percentage of redispersible polymeric cement modifier in the dry formulation be greater than that of a corresponding topping formulation, most preferably on the order of about 4 to about 8 percent by weight based on the total dry formulation.
Whether applied as a thin coating or a thick topping, in order to enhance the retroreflectivity of the marking material, the material is preferably seeded with retroreflective agents, and optionally, reflective agents, such as being broadcast on the surface prior to setting of the cementitious marking material. Suitable retroreflective agents and reflective agents are listed above, being selected from those which are capable of being incorporated integrally in the matrix of the cementitious material by formulation in the dry mix.
The marking materials of the present invention, therefore include an at least partially embedded broadcast of retroreflective filler particles having a topsize of at least about 600 microns at the surface of the topping or coating. Preferably, the retroreflective filler particles have a topsize of at least about 850 microns. Optionally, a clear coat may be applied over the broadcast particles, such as an acrylic resin or a polyurethane coating.
It has been found that the consistency of the cementitious material applied to the pavement, at the time of the seeding of the retroreflective or reflective particles, affects the depth to which the particles sink into the material, and thus the percentage of the individual particles which are embedded into the matrix. Generally, the higher the percentage of the exposed particles, the higher the initial retroreflectivity or reflectivity of the marking material. However, even a small percentage of exposed retroreflective agents, provides an acceptable reflective performance.
With wear of the pavement (and marking material) surface, both the surface embedded retroreflective agents and the retroreflective fillers incorporated in the matrix of the marking material become exposed, and perform the desired function of low light or night reflectivity or visibility. Visibility in light environments is also enhanced by the presence of the retroreflective agents. The permanence of the integrated cementitious topping or coating marking materials as compared with conventional paint or tapes is thus demonstrated.
The marking material is a cementitious material having high strength, such as compressive, tensile and flexural strength similar to the concrete pavement, with retroreflective fillers at the surface and preferably throughout the matrix for xe2x80x9creplenishmentxe2x80x9d of the surface as the surface of the marking material abrades together with the contiguous pavement. The marking material has a setting time approximately equal to concrete, and a volume stability and thermal expansion compatible with concrete. Similarly to concrete, the marking material is resistant to UV light and to de-icing salts. The incorporated polymer provides enhanced bonding to the integral particles, and also to the substrate pavement.